Directions: The question below is followed by six choices numbered 260-265. If a choice is correct, mark A in the space provided. If a choice is not correct, mark B. Blacken one circle on your answer sheet for each number.
The nurse is explaining the Bill of Rights for psychiatric patients to a client who has voluntarily sought admission to an inpatient psychiatric facility. Which of the following rights should the nurse include in the discussion

Right to obtain disability.

如图，一段导线abcd位于磁感应强度大小为B的匀强磁场中，且与磁场方向（垂直于纸面向里）垂直，线段ab、bc和cd的长度均为L，且∠abc=∠bcd=135°。流经导线的电流为I，方向如图中箭头所示。导线段abcd所受到的磁场的作用力的合力

A．方向沿纸面向上，大小为

B．方向沿纸面向上，大小为

C．方向沿纸面向下，大小为

D．方向沿纸面向下，大小为