The percentage of adult height attained by a girl who is x years old can be modeled byf(x)=61+35 log (x-3)where x represents the girl's age (from 5 to 15) and f(x) represents the percentage of her adult height. Complete parts (a) and (b) below.a. According to the model, what percentage of her adult height has a girl attained at age 12?A girl has attained% of her adult height by age 12.(Do not round until the final answer. Then round to the nearest tenth as needed.)b. Why was a logarithmic function used to model the percentage of adult height attained by a girl from ages 5 to 15, inclusive?O A. Height increases rapidly at a young age, and then increases more slowly.OB. Height increases at a steady rate, regardless of one's age.OC. Height increases rapidly at a young age, stops increasing at a certain age, and then starts decreasing.O D. Height increases rapidly at a young age, and continues to increase even faster as one gets older.