Consider The Expansion of (1+x)‏²n+1

For the next three (03) items that follow:
Consider the expansion of (1+x)‏²ⁿ⁺¹

1. If the coefficients of x^r and x^r+1 are equal in the expansion, then r is equal to
   (a)n                           (b) 2n-1/2          (c) 2n+1/2             (d) n+1
2. The average of the coefficients of the two middle terms in the expansion is
   (a) ²ⁿ⁺¹C_n+2              (b) ²ⁿ⁺¹C_n            (c) ²ⁿ⁺¹C_n-1              (d) ²ⁿC_n+1
3. The sum of the coefficients of all the terms in the expansion is

(a) 2^2n-1                       (b)4 ^n-1               (c) 2 x 4ⁿ                (d) None of the above