Verbal Aptitude

Claim: 'Constructing plastic greenhouse tunnels will ensure profitable tomato cultivation for all smallholders in the valley.' Which of the following casts the greatest doubt on this claim?

Options:

• (A) Summer temperatures inside the tunnels exceed 45$^{\circ}$C without active ventilation, causing complete blossom drop and crop failure unless expensive evaporative coolers are installed.
• (B) Plastic tunnels protect crops from light frost in winter.
• (C) Tomatoes grown under plastic have uniform red coloration.
• (D) Tunnel frames can be fabricated from galvanized iron.