Correct answer is option D.

• Martempering is also known as stepped quenching or interrupted quenching. In this process, steel is heated above the upper critical point (above the transformation  range) and then quenched in a salt, oil, or lead bath kept at a temperature of 150-300 °C.  The workpiece is held at this temperature above martensite start (Ms) point until the temperature becomes uniform throughout the cross-section of workpiece. After that it is cooled in air or oil to room temperature. The steel is then tempered. In this process,  austenite is transformed to martensite by step quenching , at a rate fast enough to avoid the formation of ferrite, pearlite  or bainite.
• Normalizing is a heat treatment used on steel so as to refine its crystal structure and produces a more uniform and desired grain size distribution. The final microstructure consists of fine pearlite.

Correct answer is option A.

• Drawing is a metalworking process which uses tensile forces to stretch metal, glass, or plastic. As the metal is drawn (pulled), it stretches thinner, into a desired shape and thickness. Drawing is classified in two types: sheet metal drawing and wire, bar, and tube drawing.
• Crankshafts are the main rotating parts of an engine that are installed on a connecting rod and can convert the up and down movement into a circular movement of the connecting rod. Typically, in the crankshaft manufacturing process, a billet of suitable size is given a heat treatment till the required forging temperature, and then it is successively pounded or pressed into the required shape by pressing the billet between a pair of dies under high pressure.
• Rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness, to make the thickness uniform, and/or to impart a desired mechanical property. The final product is either sheet or plate.
• Stretch forming is a metal forming process in which a piece of sheet metal is stretched and bent simultaneously over a die in order to form large contoured parts.

Correct answer is option B.

Grain refinement, also known as inoculation, is the set of techniques used to implement grain boundary strengthening . One method for controlling grain size in aluminium alloys is by introducing particles to serve as nucleants, such as Al–5%Ti. Grains will grow via heterogenous nucleation ; that is, for a given degree of undercooling beneath the melting temperature, aluminium particles in the melt will nucleate on the surface of the added particles. Grains will grow in the form of dendrites growing radially away from the surface of the nucleant. Solute particles can then be added (called grain refiners) which limit the growth of dendrites, leading to grain refinement. Al-Ti-B alloys are the most common grain refiner for Al alloys.