Let initially the number of women be \(w\). hence, the number of men in the bus be \(2w\).
At stop Y, 5 women board while 10 men leave,
Then,
\(w+5 = 2w - 10\)
\(⇒ w = 15\)
Thus, the total number of passengers at the beginning of the day,
\(w + 2w\)
\(⇒ 45\)
So, the correct option is (D): \(45\).

