The plants grown in soil rich with humus show dark green leaves while plants grown in soil without humus have yellow toned leaves. All of the following statements regarding these two groups of plants are true except

• A. Plants that have grown in humus-rich soil get nutrients necessary for chlorophyll development
• B. Plants that have grown in humus-free soil fail to develop chlorophyll
• C. The humus contained minerals such as magnesium and iron needed for the synthesis of chlorophyll.
• D. The humus made the soil more loosely packed, so water penetrated more easily to the roots

Answer: (D)