Which organisms have many cells that are grouped together into tissues?

The correct answer is-  Multicellular organisms.

Multicellular organisms are those, which are made up of many cells. In these organisms, cells that perform similar function are clustered together and these clusters are termed as tissues ( like muscle tissue is composed of muscle cells, which are long fibrous cell and can be excitable to perform contraction and relaxation). In words, tissue is a group/ cluster of cells that perform similar functions.

Example of multicellular organisms- Plants and animals.

the electromagnetic energy from the sun arrives in the form of visible and invisible light.