The group that includes organisms all of which are absorptive in their nutrition is fungi.

Here's why:

* Fungi are heterotrophic, meaning they cannot produce their own food. Instead, they obtain nutrients by absorbing them from their environment. They secrete enzymes that break down organic matter (like dead plants, animals, or even other fungi) into smaller molecules that they can then absorb.

Let's look at why other options are not the best fit:

* Bacteria can be both absorptive and chemotrophic (obtaining energy from chemicals).

* Plants are photosynthetic, meaning they produce their own food through sunlight.

* Animals are ingestive, meaning they take in large food particles and digest them internally.

Let me know if you'd like more details about fungi or any other aspect of nutrition!