Answer:
56
Step-by-step explanation:
28 is not a correct option because it is not a common multiple of 8.
42 is not correct because it is also not a common multiple of 8.
56 is correct option because it has two factors 2 and 7, and is the common multiple of 8 and 14 (8 x 7 = 56, 14 x 4 = 56)
48 is not correct because it is not a common multiple of 14.