Although the company began in 1912 as a mom-and-pop operation, by the mid-1950s it has been reinvented as a worker-owned conglomerate.

(A) by the mid-1950s it has been reinvented
(B) by the mid-1950s it had been reinvented
(C) by the mid-1950s it is reinvented
(D) by the mid-1950s it reinvented
(E) by the mid-1950s it became reinvented