【正确答案】 B

【答案解析】[*] **Use TACTICS 2 and 3: replace a by a number, and use 100 since the problem involves percents. 100 + (100% of 100) = 100 + 100 = 1. Test each choice; which ones equal 1 when a = 100. Both A and B: [*]. Eliminate Choices C, D, and E, and test A and B with another value for a. 50 + (50% of 50) = 50 + (25) = 2. Now, only B works[*]