I don't feel any explanation above is correct. A is not correct because of the reasons discussed above. This is a tough problem of Noun+Noun modifiers.
Here we go:
A) Margaret Courtney-Clarke has traveled to remote dwellings in the Transvaal to photograph the art of Ndebele
women, whose murals are brilliantly colored, their geometrical symmetries embellished with old and new
iconography and in a style that varies from woman to woman and house to house.
Here "whose" is modifying "women" and 'their" is modifying "murals"
"Their geometrical symmetries embellished with old and new iconography": It is a Phrase or Noun+Noun modifier modifying murals. "Embellished" is not a verb.
It is a "verb+ed" modifier. "Geometrical symmetries" cannot perform the action of embellishment, making this sentence a phrase.
"In a style that varies from woman to woman and house to house": Again a phrase modifying murals.
So, both phrases are parallel to each other modifying "murals".
By practising Noun+Noun modifiers again and again. I come to the conclusion that they make the point of the clause they are modifying more believable.
Ex1: Here, murals are brilliantly colored. How can you say that they are brilliantly colored?
A: Their geometrical symmetries embellished with old and new iconography and in a style that varies from woman to woman and house to house
Ex2: John, his arms flailing in the wind, called out desperately for help. How can his action be proved?
A: "His arms flailing in the wind" is a modifier modifying John . So, the modifier is proving John's action of calling for help.
You can look at them the way you want.
2) whose murals are brilliantly colored,
their geometrical symmetries are embellished with old and new iconography, and
their style is varying among women and houses 3) whose murals are brilliantly colored,
their geometrical symmetries are embellished with old and new iconography, and
they are in styles that vary from woman to woman and house to houseBoth modifiers in sentence 2 and 3 are clauses, and 1st is separated without "FANBOYS". If "as" is present before "their" then these sentences can be grammatically correct. However, it will change the intended meaning
Also, in 3rd sentence "they are in styles" is wordy and awkward.
4) with murals brilliantly colored,
their geometrical symmetries embellished with old and new iconography, and
their
style varies among women and houses5)with murals that are brilliantly colored,
their geometrical symmetries embellished with old and new iconography,
and
their styles vary among women and housesIn both of the sentences, the first modifier is a phrase and the second is a clause.
Hope it helps.