About how long does it take the sun to rotate once about its axis? a. 10 minutes b. 25 earth days c. 25,000 earth years d. 30 seconds

I disagree with Sushan as the sun does definitely rotate on its axis, this rotation was first detected by observing the motion of sunspots.
The period of time for it to rotate once on its axis is 25 (24.47 to be exact) earth days, so B is correct.

Extra: The rotation period is nearly 31 days near Poles, and 25 days near
the equator.

Hope this helps!