Passage (Walter Pater, *The Renaissance*, 1873, from "The School of Giorgione"): "All art constantly aspires towards the condition of music. For while in all other works of art it is possible to distinguish the matter from the form, and the understanding can always make this distinction, yet it is the constant effort of art to obliterate it. That the mere matter of a poem, for instance — its subject, its given incidents or situation; that the mere matter of a picture — the actual circumstances of an event, the actual topography of a landscape — should be nothing without the form, the spirit, of the handling; that this form, this mode of handling, should become an end in itself, should penetrate every part of the matter: this is what all art constantly strives after, and achieves in different degrees." What is the function of the second sentence (beginning "For while in all other works of art...")?

The sentence opens with *For*, the classical English word for *because*. Its purpose is therefore to **explain** the opening claim. The explanation runs: in all other arts the understanding can distinguish matter from form, *yet it is the constant effort of art to obliterate it.* Because that obliteration is harder when the materials (a story, a depicted scene) keep insisting on a separable subject, music — where the fusion is most natural — becomes the ideal that other arts pursue. - **A** misreads *yet* as a concession against Pater. It is a concession *within* his argument, not against it: yes, matter and form can be distinguished by the understanding, *but* art works against that distinguishing. - **C** is too narrow — Pater is not cataloguing media in this sentence; he is naming a shared *struggle*. - **D** would require an opponent (a formalist critic). The sentence does not respond to anyone; it explains. The move (claim → *for* + reason) is a classic GRE-RC structure: the second sentence supplies the *because* the first sentence's claim depends on.