Final answer:
The correct option is a. The initial velocity of a flea starting from rest is 0 m/s, which refers to its velocity before any forces cause it to move.
Step-by-step explanation:
Starting from rest means that the initial velocity of an object before it begins to move is zero. Therefore, the initial velocity of the flea right before it jumps is 0 m/s.
This is often a fundamental principle within physics problems dealing with motion, where 'initial velocity' typically refers to the velocity of an object before any forces are applied to initiate movement. The initial velocity of a flea starting from rest is 0 m/s, which refers to its velocity before any forces cause it to move.