I'm almost certain it's D. I hope I'm right
PIES stands for Power Initiator Explosive and Switch.
He ether typed 50 words or he typed the word 'strokes' 250 times
<span>The operand is part of the instruction and is fetched from code memory following the instruction opcode.
</span><span>The value is stored in memory, and the specific address is held in a register</span>