Question $31($Mandatory$)(0\mathrm{.}36$ points$)$

A cement company decided to modify its production methods to minimize the negative impact of the company's activities on the environment. The company also invested in the purchase of upgraded machinery to implement this plan. In the given scenario, the cement company most likely embraced the idea of

a$)$ corporate philanthropy

b$)$ planned obsolescence

C$)$ sustainable development

d$)$ cause$-$related marketing