Look at the dictionary entry that follows this sentence. What is the meaning of the word "constrains as it is used in the sentence?

"Such has been the patient sufferance of these Colonies,
and such is now the necessity which constrains them to
alter their former Systems of Government."

Thomas Jefferson, Declaration of Independence, printed
by John Dunlap, July 4, 1776, Records of the Continental
and Confederation, Congresses and the Constitutional
Convention, 1774-1789, Record Group 360, National
Archives, http://www. ourdocuments. gov/doc. php?doc=2.

con / strain (verb)

1 a: to force by imposing limitations or restrictions
b: to limit the motion of someone or something in a
particular fashion
2: to fasten with bonds: confine; LIMIT
3: to hold back with force

A. To force by imposing limitations or restrictions

B. To limit the motion of someone or something in a particular
fashion

C. To hold back with force

D. To fasten with bonds