What is the difference between a mandatory and optional referendum?

A. mandatory requires voters to decide on an issue and optional means they do not have to vote

B. optional means the legislature has an option to present a vote to the people and mandatory means all people have to vote

C. mandatory means a legislature has to present it to the people and optional means they voluntarily did it but were not required to

D. they are both measures implemented by the governor for fairness

The answer is B, "optional means the legislature has an option to present a vote to the people and mandatory means all people have to vote "

Explanation:

Both optional and mandatory referendums are part of Switzerland democracy instruments geared at ensuring the power to make decisions lie in the hands of all its citizens. Mandatory referendum is a type of referendum that the government must call in order to determine certain but important political issues while optional referendum is one which may be called by the legislature in relation  to new or amended federal acts and/or international treaties.

b europeans take corn to africa. corn becomes an important crop there.