Which of the following is/are true ? (a) Chords equidistant from the centre of a circle are equal in length. (b) The angle subtended by an arc at the centre is double the angle subtended by it at any point on the remaining part of the circle. (c) Angles in the same segment of a circle are equal. (d) Sum of either pair of opposite angles of a cyclic quadrilateral is 360°. (e) If the sum of a pair of opposite angles of quadrilateral is 90°, it is cyclic. Choose the most appropriate answer from the options given below :