Which of the following is a secondary alcohol?
(a) 3-ethyl-2-methyl-1-pentanol
(b) 3-ethyl-2-methyl-2-heptanol
(c) 3-methyl-2-hexanol
(d) 1-hexanol
(a) 3-ethyl-2-methyl-1-pentanol
(b) 3-ethyl-2-methyl-2-heptanol
(c) 3-methyl-2-hexanol
(d) 1-hexanol