In the case where the ball strikes R1 near second base after being hit by B4, what happens?

When the ball strikes R1, who is near second base, after being hit by B4, the situation is handled according to the rules governing interference and base running. Since R1 has not yet legally acquired the base, being hit by a batted ball results in R1 being declared out. This is a clear application of the rule regarding base runners being struck by a batted ball while not on a base. R1 is not in the act of advancing or attempting to avoid the ball, and as such, the contact with the ball constitutes an out for R1.

The other scenarios, such as the ball becoming dead or B4 being ruled out, do not apply in this context, as R1 is the one directly affected by the batted ball. Thus, the outcome is that R1 is out, confirming the validity of that answer.