Mycorrhizal biotechnology has been used in rehabilitating degraded sites because mycorrhiza enables the plants to 1. resist drought and increase absorptive area 2. tolerate extremes of pH 3. resist disease infestation Select the correct answer using the codes given below.

Mycorrhizal biotechnology is indeed crucial for rehabilitating degraded sites. Let's break down why:

1. Resist drought and increase absorptive area: Mycorrhizae form a symbiotic relationship with plant roots, extending the root system's reach. This significantly increases the surface area for water and nutrient absorption, enhancing drought resistance.

2. Tolerate extremes of pH: Mycorrhizal fungi can alter the rhizosphere (the area around the roots), buffering against extreme pH levels, making nutrients more available to the plant. They can thrive in both acidic and alkaline conditions, improving plant tolerance.

3. Resist disease infestation: Mycorrhizae provide a physical barrier against pathogens and can stimulate the plant's defense mechanisms, increasing resistance to root diseases. They also compete with pathogens for resources.

Therefore, all three statements are correct. Options A, B, and C are incorrect because they exclude one or more of these vital benefits. Mycorrhizae offer a holistic approach to plant health and resilience, making them invaluable in ecological restoration.