The correct answer is: B. Elastic modulus of high tensile steel is more than that of mild steel.
Elastic modulus is a measure of how much a material will deform under stress. It is calculated by dividing the stress applied to a material by the strain produced. The elastic modulus of high tensile steel is more than that of mild steel because high tensile steel has a higher yield strength. The yield strength is the stress at which a material begins to deform permanently.
Carbon percentage in high carbon steel is more than that in mild steel. This is because high carbon steel is made with more carbon than mild steel. Carbon is an alloying element that increases the strength of steel. However, it also makes the steel more brittle.
High tensile steel is not cheaper than mild steel. This is because high tensile steel is made with more expensive materials and requires more processing. However, high tensile steel is more durable than mild steel and can be used in applications where strength is more important than cost.