Treatment of 2-Hexanone with NaOCH₂CH₃ Followed by CH₃Br Affords Compound

Treatment of 2-hexanone with NaOCH₂CH₃ followed by CH₃Br affords compound X (C₇H₁₄O) as the major product. X shows a strong absorption in the IR spectrum at 1713 cm^?1, and its ¹H NMR data is given below. What is the structure of X?


$\begin{array}{llcc} \text {Signal \# } & \text { Shift (ppm) } & \text {Multiplicity } & \text {Integration }\\1&0.96& \text {triplet}&3 \mathrm{H}\\2&1.16& \text {doublet}&3 \mathrm{H}\\3&1.33& \text {multiplet}&2 \mathrm{H}\\4&1.53&\text {multiplet}&2 \mathrm{H}\\5&2.09& \text {singlet}&3 \mathrm{H}\\6&2.52& \text {multiplet}&1 \mathrm{H}\end{array}$

A) IV
B) III
C) II
D) I