After the Canadian Content Regulations Came into Effect in 1971,what

Multiple Choice

After the Canadian content regulations came into effect in 1971,what happened to the number of Canadian number-one singles on the CHUM charts in the following 13-year period?

A) They dropped from 35 to 25.
B) They dropped from 19 to 13.
C) They increased from 13 to 19.
D) They doubled from 15 to 30.
E) They more than tripled from 11 to 35.