Endodermis location in root water transport pathway

Steps:

• Recall root structure: water enters via epidermis, moves through cortex, reaches endodermis with Casparian strip, then enters vascular tissue.
• Identify endodermis as innermost cortex layer blocking apoplastic flow, forcing symplastic entry to xylem.
• Trace pathway in diagram: label cells sequentially from outer root to xylem core.
• Match endodermis to cell layer just before pericycle/xylem.

Why C is correct:

• Endodermis is defined as the cortex's inner layer with Casparian strips regulating water entry to stele.

Why the others are wrong:

• A: Epidermis, outermost layer for initial water absorption.
• B: Cortex cell, middle layer for bulk water movement.
• D: Pericycle or vascular cell, inner layer post-endodermis toward xylem.

Final answer: C