Answer

Further explanation
As an exponential expression, we'd write 6 × 6 × 6 × 6 as:
6⁴
because:
We multiply 6 by itself 4 times. That's indicated by the exponent ⁴.
Recall that the exponent tells us how many times the base was multiplied by itself.
Since the exponent says 4, then the base (6) has been multiplied by itself 4 times.
Therefore, the answer is the third option.