Which of the following statements is FALSE?

a.
After General Cos surrendered during the Texas Revolution, Mexico ignored the legislative act setting the southwestern boundary of Texas at the Rio Grande .
b.
In 1850 Washington D.C. abolished slavery.
c.
After the U.S. Mexican war, Mexico ceded the upper portion of California and parts of New Mexico to the U.S. for $15 million.
d.
There was strong opposition to the war with Mexico within the U.S. from the Whig party