An investment firm recommends that a client invest in AAA-, A-, and B-rated bonds. The average yield on AAA bonds is 6%, on A bonds 6.5%, and on B bonds 8%. The client wants to invest twice as much in AAA bonds as in B bonds. How much should be invested in each type of bond under the following conditions? Complete parts (a) through (c) below. a. The total investment is $27,000, and the investor wants an annual return of $1780 on the three investments. Let 2x represent the amount invested in AAA bonds, y be the amount invested in A bonds, and x be the amount invested into B bonds. Write a system of linear equations. Choose the correct answer below. A. 0.06(2x) + 0.065y + 0.08x = 1780 2x + y +x= 27,000 O B. 0.06x + 0.065y + 0.08x = 27,000 2x +y+x = 1780 Oc. 0.06(2x) +0.065y + x = 1780 4x +y +0.08x = 27,000 O D. 2x+y +0.08x = 1780 0.06(2x) +0.065y +x= 27,000 They should invest $ 10000 at 6%, $ 12000 at 6.5%, and $ 5000 at 8%. b. The values in part (a) are changed to $30,000 and $1985, respectively. They should invest $ 14000 at 6%, $ 9000 at 6.5%, and $ 7000 at 8%. c. The values in part (a) are changed to $39,000 and $2595, respectively. They should invest S at 6%, S at 6.5%, and S at 8%.