The most advanced group of algae is Chlorophyta.

Chlorophyta:

Chlorophyta is a large and diverse group of algae that includes over 7,000 species. They are found in a variety of habitats, including freshwater, marine, and terrestrial environments. Chlorophyta are also known as green algae because they contain chlorophyll a and b, which gives them their green color.

Characteristics:

- Chlorophyta are unicellular or multicellular organisms.
- They have a cell wall made of cellulose.
- Chlorophyta have chloroplasts, which contain chlorophyll a and b, and other pigments.
- They reproduce sexually or asexually.
- They can reproduce by fragmentation, which is the breaking up of the organism into smaller pieces that can grow into new individuals.

Importance:

- Chlorophyta are important primary producers in aquatic ecosystems.
- They are used as bioindicators to monitor water quality.
- Some species are used in food production, such as Nori (Porphyra) and Spirulina.
- Chlorophyta are also used in research, particularly in the study of photosynthesis.

Conclusion:

Chlorophyta is the most advanced group of algae due to their complex cellular organization, diverse habitat range, and the presence of chlorophyll a and b. They play a significant role in aquatic ecosystems and have various uses in food production and research.

Ok answer is b not c and let me explain why answer is b Chlorophyta also known as green algae is called as most advanced algae because of the follwing reasons chlorophyta have chlorophylls a and b and store starch as a reserve food material inside thier plastids. and also it is a diverse group of algae and most of them are fresh water forms  the plant body is motile and unicelullar  for example chlamydomonas  and also, the cells possess one to many chloroplasts which occur in characteristic shapes in different forms this is the main reason and no other algae exhibit many chloroplasts like chloroplyst thanks!