In the Late 1950s and 1960s, Television Westerns Were Extremely

In the late 1950s and 1960s, television westerns were extremely popular and included Gunsmoke, Bonanza, Wagon Train, and The Big Valley. When ratings declined as viewers' tastes changed, production of them waned. The television western was a product category that had entered the ________ stage of its product life cycle.

A) deletion
B) cancellation
C) decline
D) maturity
E) harvesting