To solve this problem, we need to identify the specialized epidermal cells that surround the guard cells. Let's analyze the options:$\newline \bullet$Option 1: Complementary cells$\newline$ - Complementary cells are not associated with guard cells. They are part of the periderm and help in gas exchange through lenticels.$\newline \bullet$Option 2: Subsidiary cells$\newline$ - Subsidiary cells are specialized epidermal cells that surround the guard cells. They assist in the functioning of the stomata by providing structural support and regulating the opening and closing of the stomatal pore.$\newline \bullet$Option 3: Bulliform cells$\newline$ - Bulliform cells are large, bubble-shaped epidermal cells found in the leaves of grasses. They help in the rolling and unrolling of leaves to minimize water loss.$\newline \bullet$Option 4: Lenticels$\newline$ - Lenticels are openings in the bark of woody plants that allow gas exchange. They are not related to guard cells.$\newline$Based on the analysis, the correct answer is Option 2: Subsidiary cells. These cells are specifically associated with guard cells and play a crucial role in stomatal function.