You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

Q: Question: Let f(x) = x^2 + bx + c. If f(1) = 0 and f(-8) = 0, then f(x) crosses the y-axis at what y-coordinate?

 Option A: -8

 Option B: -1

 Option C: 0

 Option D: 1

 Option E: 8

A: Option A
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Q: Question: If x is positive and y is negative, which of the following must be true?

 Option A: The product of x and y is positive

 Option B: The sum of x and y is positive

 Option C: The sum of x and y is negative

 Option D: The difference of x and y is positive

 Option E: The sum of x^2 and y^2 is positive

A: Option E
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Q: Question: The speed at which a man can row a boat in still water is 150 kmph. If he rows downstream, where the speed of current is 48 kmph, what time will he take to cover 390 metres?

 Option A: 10

 Option B: 11

 Option C: 12

 Option D: 13

 Option E: 14

A:
Option D
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