The correct answer to this open question is the following.
Although you forgot to attach the options for this question we can say the following.
The statement that best explains how the near 36% population gain in the United States between 1840 and 1850 led to the compromise of 1850 is the following: "The pace of population growth between 1840 and 1850 required the U.S. Congress to revisit the protocols for the collection of census data. The new protocols were incorporated into the Compromise of 1850."
In the difficult and turbulent years prior to the American Civil War, when we are talking about the Compromise of 1850, we are referring to the laws the US Congress passed in the month of September 1850, addressing the complicated issues of territorial expansion and slavery.
Senator Henry Clay was the legislator that introduced the series of legislation that became the Compromise of 1850 trying to avoid a severe confrontation between the states. After the approval of the Compromise, the Washington slave trade was prohibited and the Fugitive Slave Act had to be amended.