Research into the Neural Differences Between Self Vs

Research into the neural differences between self vs.other considerations is difficult due to many potential biases.Which of the following is a not a bias in self vs.other thinking:

A) People tend to think more positively of themselves than others
B) People explain their own behavior based on personal attributes and others' behavior based on social context
C) People are more familiar with themselves than others
D) When we think about ourselves we use more recent memories, whereas in thinking of others we use more distant memories