The correct answer is C. 
It reaches sexual maturity at 15 years of age. 
K-Selection is termed as the selection of combination of traits in an organism.
 They trade off between quality and quantity of offspring. This theory was used as a heuristic device. K-selection theory, selective pressure are hypothesized to drive evolution in one generalized direction. 
The best example which illustrates this k-selection is a polar bear producing one two cubs for every period of three years.