Which two expressions each represent 3/21 ?

A) 3⟌21 and 21 ÷ 3

B) 3⟌21 and 3 ÷ 21

C) 21⟌3 and 3 ÷ 21

D) 21⟌3 and 21 ÷ 3
Please help!

Long division setup showing an incomplete calculation. 12 is in the divisor, 6839 is in the dividend, and 5 hundreds and 6 tens is written in the quotient. 6000 is subtracted from 6839 to give 839. an unknown value represented by a box is being subtracted from 839. what number should be placed in the box to complete the division calculation?