と～と、どちらが Between ~ which one

と～と、どちらが is an expression in Japanese that is made from the following parts:

と - The particle (x2) in its meaning of 'and'.

どちら - The polite speech form of 誰(だれ) 'who', and a slightly newer form of どっち that basically means 'which'.

が - The case marking particle.

This structure is used when the speaker is asking a question about whether someone will choose (A) or (B). It is only used when there are no more than two possible choices.

As can be seen above, verbs may be used as part of this structure if they are nominalized with こと, or の. Additionally, the polite form does not specifically need to be used, and どっち may be used instead.

The second と itself is quite often omitted, as どちら (or どっち) implies that both (A) and (B) are part of the same structure.

Fun Fact

As どちら is the polite speech form of 誰(だれ), it is also frequently used as a polite way to ask questions about unknown people.

Caution

どちらのほう (or どっちのほう) may also be used, but this does not really change the overall nuance. It merely puts slightly more emphasis on the 'direction' of the choice. This is similar to expressions like 'which one are you leaning towards?' in English.