Answer:
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.