The statements of pseudocode for searching the first element with key k in the linked list L are given below. Arrange them in the correct order.
(A) while (x != NIL and x.key != k)
(B) x = L.head
(C) x = x.next
(D) return x
Consider the problem of reversing a singly linked list. To take an example, given the linked list below,

The reversed linked list should look like

Which one of the following statements is TRUE about the time complexity of algorithms that solve the above problem in \( O(1) \) space?
Rearrange the following parts to form a meaningful and grammatically correct sentence:
P. a healthy diet and regular exercise
Q. are important habits
R. that help maintain good physical and mental health
S. especially in today's busy world