The District Collector made it clear that the Government cannot sustain for long the support for such schemes.

Answer: Option D

Pay : give (someone) money that is due for work done, goods received, or a debt incurred.
Succeed : achieve the desired aim or result.
Manage : be in charge of (a business, organization, or undertaking); run.
Continue : persist in an activity or process.
Sustain : cause to continue for an extended period or without interruption.

Synonym of Sustain is Continue