Question

Circulation, Excretion, Sensation, Reproduction​

Answer 1

${\huge{\underline{\underline{\mathcal{\blue{AnsweR::}}}}}}$

$\tt\implies$ ${\huge{\boxed{\red{\mathrm{Sensation}}}}}$

Explanation-

Sensation is the external process that is caused by sense organs and others are internal processes that are carried by different underlying body parts.