How Are the Terms Demand Characteristics and Experimenter Expectancy Related

How are the terms demand characteristics and experimenter expectancy related to each other?

A) When experimenters clearly prefer participants who have certain cognitive characteristics,the experimenters expect them to perform especially well.
B) If the participants are especially demanding or difficult,the experimenter tends to have lower expectations about their performance.
C) It is unethical for an experimenter to have certain expectations,just as it is unethical for participants to make demand characteristics.
D) The experimenter's expectancy about a study's results may be one kind of demand characteristic.