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20 10 new curriculum standard mathematics text
B/a is the base of logarithm, ∴ b/a > 0 a, and b has the same sign.

The axis of symmetry of parabola -B/2A < 0 does not include AB on the left.

Both c and d have F (- 1) > 0, that is, A-B > 0, ∴ a > b.

According to the following classification, if a > 0 and b > 0, then 0 < b/a < 1 parabola opens upward and the logarithmic function decreases by d.

If a < 0 and b < 0, then b/a > 1, that is, when the parabolic opening is downward, the logarithmic function should increase.

So choose d