Which of the following examples best illustrates the principle of proper mass in brain function? Question 11 options: a) The brain of an elephant weighs more than the brain of a mouse. b) The hippocampus of taxi drivers in London is the same size of the hippocampus of humans on average, despite their extensive spatial memory requirements. c) The language areas in the human brain are more developed compared to those in non-human primates. d) The hippocampus of chimps is smaller than the hippocampus of humans, despite chimps' superior performance in working memory tasks.