Find the synonym of the underlined word.
An ultimatum given by one country to another usually includes a demand for action.
 a. Shipment of
b. Understanding of
c. Request for
d. Burden of
e. Tolerance on

Hint: Synonyms are words or phrases that mean exactly or nearly the same as another word or
phrase.

Complete step by step solution:
In the given question, the phrase ‘demand for’ refers to an urgent or peremptory request.
Let us analyze the options given to us in this question:
Option (a.), 'shipment of', refers to the act of sending off something.
Therefore, option (a.) is incorrect as its meaning is not synonymous to that of the given phrase ‘demand for’.
Option (b.), ‘understanding of', refers to a statement (oral or written) of an exchange of promises.
Therefore, option (b.) is incorrect as its meaning is not synonymous to that of the given phrase ‘demand for’.

Option (c.), ‘request for', refers to a formal message requesting something that is submitted to an authority.
Therefore, option (c.) is correct as its meaning is synonymous to that of the given phrase ‘demand for’.

Option (d.), ‘burden of', refers to an onerous or difficult concern.
Therefore, option (d.) is incorrect as its meaning is not synonymous to that of the given phrase ‘demand for’.
Option (e.), ‘tolerance on’, refers to willingness to recognize and respect the beliefs or practices of others.
Therefore, option (e.) is incorrect as its meaning is not synonymous to that of the given phrase ‘demand for’.

Note: In this question, keep in mind that when the ‘country’ gives an ultimatum, they usually have a ‘demand for’ action. This does not refer to a concern(burden of), permissiveness (tolerance on), understanding or a shipment, but instead an immediate request for action. This is why the right answer is option (c.).