Main difference between unicellular organisms and multicellular organisms

Unicellular organisms are made up of only one cell that carries out all of the functions needed by the organism, while multicellular organisms use many different cells to function. Unicellular organisms include bacteria, protists, and yeast.

Explanation:

so we know the answer cannot be c because no insect or animal starts as an adult

the answer is a. a swimming larvae

because since they are sea animals they automatticaly have to know how to swim they cannot just sink to the bottom

sorry if this is the incorrect answer.

ia. mver.y..sor .r..yinee..i am.ina.rush.pleas eforg.ive   meiknowiama. nas.s holei apalo.gize