I have a question relating to a RC question from a MGMAT Cat.

The passage does NOT indicate which of the following concerning Mexico’s current demographics?
a) Due to the government’s family planning campaign, Mexico’s population is currently diminishing.
b) On average, Mexican women are having approximately one-third the number of children that they had in 1968.
c) Many Mexicans still migrate to the United States in search of work.
d) As a result of declining birth rates, Mexico’s population is aging.
e) A healthy middle class in Mexico has not yet fully developed.


While the correct answer is A, I do not understand why C is incorrect. The explanation suggests that the first sentence precludes it:

"For years, U.S. employers have counted on a steady flow of labor from Mexico willing to accept low-skilled, low paying jobs."

however, isn't this sentence in the past tense? "For years, employers have counted on..." Answer choice C says that Many still migrate to the US (present tense)...

"have counted" is the present perfect tense. Present perfect denotes an action that began in the past but is still true or still going on right now, in the present.