How many routes are there from the lower-left corner to the upper-right corner of an mn grid in which we restricted to traveling only to the right or upward?

What changes occur in the brain during the teenage years? 25 points, someone me out!a.) thinking becomes slower as the brain grows larger. b.) connections between neurons become stronger and faster. c.) unused neurons fuse together to form larger, better functioning neurons. d.) more neurons are developed.