单选题

What is the output of the following piece of C++ code?

Question

What is the output of the following piece of C++ code?

using namespace std 
struct Item { 
    char c 
    Item *next 
} 
Item *Routine1(Item *x) { 
    Item *prev = NULL, *curr = x 
    while (curr) { 
        Item *next = curr->next 
        curr->next = prev 
        prev = curr 
        curr = next 
    } 
    return prev
} 
void Routine2(Item *x) { 
    Item *curr = x 
    while (curr) { 
         cout << curr->c << ” “ 
         curr = curr->next 
    } 
} 
int main(void) { 
    Item *x, d = {‘d’, NULL}, c = {‘c’, &d}, b = {‘b’, &c}, a = {‘a’, &b} 
    x = Routine1(&a) 
    Routine2(x) 
    return 0
}

A. cbad

B. badc

C. dbca

D. abcd

E. dcba