The correct option is A journal
Sales day book is the subsidiary book. Subsidiary books are the sub-divisions of "Journal". These books are meant for recording the transactions of similar nature in a separate book. When there are many transactions, the journal is divided into subsidiary books to record such voluminous and events in one single book. these books also called as " Special journal or Special purpose book or Book of original or Prime entry". For e.g. All the cash transactions are recorded in one book i.e. Cash book. Thus cash book, sales book, purchase book etc. are examples of subsidiary book.