Select the most appropriate option to fill in the blank.

John ran pretty fast, ______________ he did not win the race.

though

The most appropriate option to fill in the blank is though.

The word "though" is used to introduce a contrast or concession. This is the most appropriate word because it accurately describes the situation in the sentence. John ran pretty fast, but he did not win the race.

The other options are not as appropriate.

• So means therefore or consequently. It does not make sense in the context of the sentence, because John running pretty fast does not necessarily mean that he won the race.
• For means because. It does not make sense in the context of the sentence, because John running pretty fast is not the reason why he did not win the race.
• And means in addition to. It does not make sense in the context of the sentence, because John running pretty fast is not an additional fact.