If I remember correctly, the correct answer is either:
A. Electrostatic
or
B. Gravitational
Force is (mass × acceleration) measured in Newton
Pressure is the 'force' per unit area measured in Newton/m^2 (pascal)
I always thought that 'polygamy' refers to the social system in which a man
may have more than one wife, and I thought there's some other word for
where a woman is married to more than one man.
But when I went to look it up just now to answer your question, (which by the
way you could also have done very easily), I found a definition that says it's a
"state of marriage between many spouses". That doesn't specify genders, so
I guess it means any marriage that involves more than two people, no matter
how the genders may be represented or distributed within it.