To find the probability of picking a consonant from the sample space \( S = {a, b, c, d, e, f} \), we first need to identify the consonants in this set.
The letters in the sample space can be categorized as follows:
- Vowels: \( a, e \)
- Consonants: \( b, c, d, f \)
There are 4 consonants \( (b, c, d, f) \) and 6 total letters in the sample space.
The probability \( P \) of picking a consonant is given by the formula:
\[ P(\text{consonant}) = \frac{\text{Number of consonants}}{\text{Total number of outcomes}} = \frac{4}{6} \]
This fraction can be simplified:
\[ \frac{4}{6} = \frac{2}{3} \]
Therefore, the probability of picking a consonant is \( \frac{2}{3} \).
The correct response is \( \frac{2}{3} \).