Most diverse organisms of an ecosystem are

What could be the reason for the faster rate of decomposition in the tropics?

The organisms which physically and chemically break down complex dead organic remains are known as:

The decomposition of organic compounds in the presence of $O_2$ without the development of odoriferous substances is known as:

Select the incorrect statement regarding humus.

Match List-$I$ with List-$II$ :

List-$I$	List-$II$
$A$. Decomposition	$I$. Accumulation of dark coloured amorphous colloidal substance
$B$. Detritus	$II$. Release of inorganic nutrients by the activity of microbes in soil
$C$. Mineralisation	$III$. Breaking down of complex organic matter into inorganic substances
$D$. Humification	$IV$. Dead remains of plants and animals including fecal matter

Choose the correct answer from the options given below :