A psychiatric disorder in which debilitating anxiety and fear arise frequently and without reasonable cause. *
Panic Disorder
Autism
Tourette's
w
Alzheimer's

Panic Disorder (I think)

Explanation:

Panic Disorder is described as " a type of anxiety disorder. It causes panic attacks, which are sudden feelings of terror when there is no real danger. You may feel as if you are losing control. You may also have physical symptoms, such as Fast heartbeat, shaking or sweating." - Google Search

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.