\eqalign{ & {\text{If }}a + 2b\, = 6\,{\text{and }}ab = 4{\text{,}} \cr & {\text{then what is }}\frac{2}{a} + \frac{1}{b} = ? \cr} $$

• A. 1/2
• B. 1/3
• C. 3/2
• D. 2
• E. 5/2