Choose the correct sentences from the options:
$(1)$ Decomposition is largely an oxygen-requiring process.
$(2)$ Warm and moist environment slows down the decomposition process.
$(3)$ Decomposition rate is slower if detritus is rich in lignin and chitin.
$(4)$ Humus is colloidal in nature and it serves as a reservoir of nutrients.

• A
  $1, 2, 3$
• B
  $1, 2, 4$
• C
  $2, 3, 4$
• D
  $1, 3, 4$