Equivalent expressions I

This task is about simplifying algebraic expressions.
a) The expression 3a × 4b is equal to (Circle one)
  
  (A) 7ab 
 
(B) 12ab  (C) 12ab   (D) 12b (E) 7(a + b) 
(F) 12(a + b) 
 
 
b) The expression 7p - 4p is equal to (Circle one)
 
  (A) 3p
 
(B) 11 (C) 28p (D) 3p2 (E) 11p2 
(F) 28p2
 
 
c) The expression 5m + 3m is equal to (Circle one)
 
  (A) 8m
 
(B) 15m (C) 8m2 (D) 15m2 (E) 8mm
(F) 15mm
 
 
d) The expression 8t ÷ 4t is equal to (Circle one)
 
  (A) 2t
  
(B) 2t2 (C) 2tt (D) 2 ÷ t (E) 2