Humid subtropical climates are home to

dense shrubs.
thick coniferous forests.
grasslands and few trees.
coniferous and deciduous trees.

Coniferous and deciduous trees.

Explanation:

Coniferous trees are the trees that are evergreen and bear seeds in the form of cones and are needle-leaved. These trees remain green throughout the year. These trees spread their seeds by shedding cones. Such trees are found in the areas with the moderate to high precipitation annually such as in Canada, USA, Asia, etc. The climatic condition under which these trees grow in humid conditions.

Examples of Coniferous trees are Fraser Firs, Redwoods, etc.

Deciduous trees are those trees that shed their leaves and change the color during fall. The term 'deciduous' is derived from the Latin which means 'to fall.' The tree is known for its shedding off and changing color of their leaves. The climatic condition in which these trees grow is humid weather. These trees are found in Asia, Europe, US.

Example of Deciduous trees are Black Walnut Trees, Maple, Oak, etc.

So, the correct answer is 'coniferous and deciduous trees.