What do old human brains and old beagle’s brains have in common?

Responses
A fewer neural tangles in the brains and the inability to learn new tricksfewer neural tangles in the brains and the inability to learn new tricks
B more frequent senile plaques in the brains of those with learning and memory problemsmore frequent senile plaques in the brains of those with learning and memory problems
C greater ability to make errors in small, everyday tasks like seeking a rewardgreater ability to make errors in small, everyday tasks like seeking a reward
D rapid improvements in their ability to modify their behaviors

A fewer neural tangles in the brains and the inability to learn new tricks