Question Statement:
Read the passage and answer the question:
"Photosynthetic efficiency in $C_3$ crop plants such as wheat and rice is fundamentally constrained by the oxygenase activity of the enzyme Rubisco. Under elevated ambient temperatures, Rubisco increasingly binds molecular oxygen instead of carbon dioxide, initiating photorespiration which dissipates up to $30\%$ of captured light energy without generating ATP. In contrast, $C_4$ plants like maize and sugarcane utilize an anatomical bundle-sheath carbon-concentrating mechanism that suppresses photorespiration almost entirely."
According to the passage, the primary physiological reason $C_4$ plants exhibit superior photosynthetic efficiency under elevated temperatures is that:
Options:
- (A) They lack the enzyme Rubisco in all internal photosynthetic cells.
- (B) Their anatomical bundle-sheath carbon-concentrating mechanism suppresses photorespiration.
- (C) They do not require atmospheric carbon dioxide for carbon assimilation.
- (D) They produce high amounts of molecular oxygen during the light reactions.