Answer: A. Dimerization (1), DNA binding (4), cAMP binding (3
Explanation:
It is a sphere to be precise.
Because of the omnidirectional nature of the gravitational attraction, mass tends to form spheres in the macro scale of planets and similarly massive celestial bodies.
It means that two or more cells connected together.
You can look at the word 'cell' and 'conjunctions' separately. 'Cell' is a tiny particle. 'Conjunctions' means 'two or more things connected', so just put the two meanings together.
Hope this helps. :)