After the company recalled one of its best-selling products, it would be forced to accept a one billion dollar loss, an expense that would have forced its main competitor to declare bankruptcy if it had suffered such a loss.

(A) After the company recalled one of its best-selling products, it would be forced to accept a one billion dollar loss, an expense that would have forced its main competitor to declare bankruptcy if it had suffered such a loss.

(B) As the company recalled one of its best-selling products, it accepted a one billion dollar loss; forcing its main competitor to declare bankruptcy if it had suffered such a loss.

(C) After the company recalled one of its best-selling products, its one billion dollar loss would have to be accepted; such a loss would have forced its main competitor to declare bankruptcy.

(D) After the company recalled one of its best-selling products, it was forced to accept a one billion dollar loss; its main competitor would have been forced to declare bankruptcy if it had suffered such a loss.

(E) When the company recalled one of its best-selling products, a one billion dollar loss it was forced to accept, an expense that would have forced its main competitor into bankruptcy.

OA is D
Experts pls. explain the meaning conveyed by A and D (considering changes in tense only).