The correct option is D both a and c
The guard cells are specialized cells present in epidermis of leaves. The two guard cells enclose a pore in between them, known as stomatal pore. This pore helps in the exchange of gases.
The guard cells are bean or dumbbell shaped whereas the epidermal cells are irregularly shaped cells.
The guard cells have chloroplasts and are capable of carrying out photosynthesis. The epidermal cells lack chloroplasts which makes them incapable of synthesizing food by photosynthesis.
Every cell undergoes cellular respiration and generates ATP.