$*)$ What is the primary method in which airlines adjust to short$-$term fluctuations in customer demand?

a$)$ postponement of service

c$)$ denial of service

b$)$ personnel availability

d$)$ changes in inventory

$*)$ Which of the following attributes is NOT for lean operations?

a$.$ Develop worker flexibility.

c$.$ Build processes that increase variability.

b$.$ Empower employees.

d$.$ Develop collaborative partnerships with suppliers