Most countries have outlawed whaling but some countries have few or no laws protecting whales. why are conservation pushing for worldwide restrictions on whaling.
a. whale oil is desperate needed as fuel as worldwide
b. unrestricted whaling could lead to their extinction
c. oceans are overpopulated with whales and their numbers need to be reduced or many will starve
d. whales are dangerous threats to fishing grounds.

C) Unrestricted whaling could lead to their extinction.

Explanation:

The whaling is a process of hunting and killing whales so as to get the meat, oil and whalebone so that they can be sell it out commercially. The trade of whale resources was firstly in France and Spain in 16th century but they have been spread worldwide. However, the conservation groups worldwide are pushing the restriction on whaling as unrestricted whaling can lead to complete extinction of the whale species from the Earth.

your answer is "the 1950's"