Witch of the following is the best definition of a scientific theory?

How do antiviral drugs work? in your own words.

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons

In the sentence "a mining company will consider the distribution of coal when deciding how to mine the coal," what does the word distribution mean?