Answer to PQR puzzle

Yeo Hui gets the -virtual- cake for solving the problem first. Mr. Person has again provided the most publishable solution:

It was easy enough to test the cases here. There are only 4 possibilities--444, 555, 777, and 888--that could possibly give three-digit quotients with all digits being different. Looks like it's 444: 148 x 3 = 444.

The answer is therefore C. 13

Elias.