Six film stars, Juhi (J), Kareena (K), Mahima (M), Sonali (S), Twinkle (T) and Urmila (U), are watching a preview of a Hindi movie in a theatre. There are eight seats in four rows, numbered 1–4 and each row has two seats. Seating arrangement is made according to the following conditions.
(i) K must sit in the same row as S.
(ii) M cannot sit in the same row as T.
(iii) J must sit alone in a row.
(iv) The rows with only one film star must be rows 1 and 3 only.
How many film stars are eligible to be assigned to sit in the same row with U?