Which of these statements is correct? a. the amount of carbon on earth is essentially constant. b. the amount of carbon on earth fluctuates with the seasons. c. the amount of carbon on earth is increasing due to plant and animal growth. d. the amount of carbon on earth is decreasing due to consumption of carbon based fuels. e. both b and c are correct.

Benzonitrile (c6h5cn) is reduced to two different products depending on the reducing agent used. treatment with lithium aluminum hydride followed by water forms k, which has a molecular ion in its mass spectrum at 107 and the following ir absorptions: 3373, 3290, 3062, 2920, and 1600 cm-1. treatment with a milder reducing agent forms l, which has a molecular ion in its mass spectrum at 106 and the following ir absorptions: 3086, 2850, 2820, 2736, 1703, and 1600 cm-1. l shows fragments in its mass spectrum at m/z = 105 and 77. propose structures for k and l and choose an explanation for how this could be concluded.