Generally speaking, when using a twist drill to bore a hole in metal, the harder the metal, the greater the drill's required __________.

Correct Answer: Option A — included point angle

Harder metals require a larger included point angle to provide more support for the cutting edge and to dissipate heat effectively. A flatter, more obtuse angle increases the strength of the drill point, preventing premature chipping or dulling when subjected to the higher forces required for harder materials.