Some kayakers coat the bottom of their kayaks with wax to make them more slippery. Kayakers wax their boats to

Areduce the work output.
Breduce the weight of the kayak.
Creduce their input force.
Dreduce the speed the boat travels in water.

Verified Answer :

the answer is : C. reduce their input force
they put wax on their kayak to make their boat cut smoothly through the water, which make it able to obtain further distance with less input force, which will increase it's overall speed

CReduce their input force.

Hope I could help :)