1. This is an OG question. You may see no choice contains the 'will rise' option. So, this must be an acceptable version. In some connotations, even the simple present may stand for future events. Like, the school reopens middle of next, month or Hilary is expected to run for the Prez in 2016.
2. There is also a view that only when we use the fanboy connector ‘and’ should we really look for strict physical //ism, such as in this case, 'will drop and will rise'. But when we use the subordinate connector while, we can still validly use the present tense rises.
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