Answer:
The correct answer would be Tissue.
In the cellular organization, tissue comes in after cells and before organs.
it refers to the assembly of similar cells which carry out the same or common function.
Similarly, when similar tissues work in synchronization to perform a particular function, the assembly is termed as an organ.
For example, the heart is an organ used to pump blood. It is made up of cardiac tissue which helps in synchronized contraction of the heart.