Select the exact numbers from the following:
(a) the mass of a black ballpen
(b) the average height of buildings around the park
(c) the number of liters in a cubic feet of water
(d) the number of employee in an office
(e) the mass of a soda can

• A. a & e
• B. c & d
• C. b & c
• D. a & d

Answer: (B)