What is the definition of body mechanics? the process of helping residents use their bodies correctly
the use of the body to prevent injury
people who make mechanical devices for the body
the use of mechanical devices to move the body

Body mechanics refers to the way you hold your body when you move around. 

answer: d is correct

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.