Final answer:
The ratio of 49 rainy days out of 70 days can be written as the fraction 7/10 in simplest form.
Step-by-step explanation:
To write the ratio as a fraction in simplest form, we divide the number of rainy days (49) by the total number of days (70). The ratio is therefore 49/70. Since both numbers have a common factor of 7, we can simplify the fraction by dividing both the numerator and denominator by 7.
This gives us the simplified fraction of 7/10.
Therefore, the correct answer is A. 7/10.