The structural formula, with atoms A, B, and C unspecified, is

H B H
H- C- C- C- H
A Br C

The formula is C3H6Br2. If the compounds is called 1,2-dibromopropane, A, B, and C
must be
A. A = H; B = Br; C = H. C. A = Br; B = H; C = H.
B. A = H; B = H; C = Br. D. A = Br; B = H; C = Br.

Did you try spacing and couldn't?