What is the most appropriate advice for the mother of a 6-month-old infant who consistently wants to put everything in his mouth?

A) Encourage the baby to continue mouthing behavior as it is a natural developmental stage.
B) Introduce small, safe objects for the baby to explore with his mouth under close supervision.
C) Strictly discourage the baby from mouthing behavior to avoid potential hazards.
D) Provide teething toys and objects designed for oral exploration to satisfy the baby's urge safely.