Which of the following statements concerning the selection of industrial channel structures is$($are$)$ true?

all of the answer choices.

Frequently, the manager has little flexibility in the selection because of trade, competitive, company, and environmental factors.

Both frequently, the manager has little flexibility in the selection because of trade, competitive, company, and environmental factors and competitors often have the better intermediaries "locked up$."$

The channel should be viewed as a set of channel institutions rather than as a sequence of activities to be performed.

Competitors often have the better intermediaries "locked up$."$