Question

Read the excerpt from part one of Trifles. COUNTY ATTORNEY (with the gallantry of a young politician). And yet, for all their worries, what would we do without the ladies? What is the primary purpose of these stage directions?
to further establish the time period
to indicate a character’s tone of voice
to direct actions that take place onstage
to describe a character’s thoughts

Answer 1

It's "to indicate a character's tone of voice". he is trying be snarky about the women.

Answer 2

to indicate a character’s tone of voice

The stage directions are found inside of the parentheses "(with the gallantry of a young politician)". The use of the preposition "with" tells us that the following lines should be said as if the character has "the gallantry of a young politician". This means that there should be some arrogance and courage behind his question. In a way he's saving the women, but also acknowledging their troublesome traits..