In a population of animals p = 0.7. The introduction of a predator to the environment causes the fitness of homozygous recessive individuals to have a fitness of 0.3 and homozygous dominant individuals to have a fitness of 0.5. Heterozygous individuals have a fitness = 1. One generation after the introduction of the predator, what proportion of the population will be heterozygous? 
A) 66% 
B) 34% 
C) 21% 
D) 45% 
E) 42%