The bottleneck effect can be explained by the cheetah population. Cheetah's used to be unique and many before they were hunted. Their population dropped so low, breeding produced almost exact 'clones'. The bottleneck effect is when genetic diversity is lost.
The tangent function is periodic with a period of 180°, so tan(100°) will be equal to tan(100°+k·180°) for any integer k. Answer choices include k values of ±1, so two of them are correct: