Yesterday's answer is B.
Today's question.
B1 hits a ball to CF - it is caught. The base umpire notices the CF has a 1st baseman's mitt.
a. B1 is out - mitt must be removed.
b. The offense has the option to replay the pitch.
c. B1 is awarded 3 bases - illegal equipment.
d. No infraction. Any player may use a 1st baseman's mitt.