b 1 & gt； b2 & gtb3

This kind of topic, because it is a multiple-choice question, must be

In the shortest time, you should use the special value method to choose the answer, that is, you give each letter a specific value that meets the conditions and substitute it for calculation.

Let a 1=3 a2=2 a3= 1.

b 1=4 b2=3 b3=2

A 3*2+2*3+ 1*4= 16

B 12+6+2=20

C 9+6+4= 19

D 8+3+6= 17

The answer is B.

In fact, the so-called product can be understood as n times of a number without a special value method.

The larger the confirmation number, the larger the magnification and the larger the value. The so-called strong alliance, definitely choose B.