How is π{A, C}(R) interpreted if relation R(A, B, C) contains tuples?

In relational algebra, the projection operator denoted by π (pi) is used to select specific columns from a relation while discarding the others. When we write π_{A, C}(R), where R is a relation with attributes A, B, and C, the operation instructs us to retrieve only the data contained in columns A and C from every tuple in R. Consequently, column B is excluded from the result set. This matches Option A perfectly as it describes outputting only columns A and C while discarding B.

Option B is incorrect because projection does not compute new attributes; it merely selects existing ones.

Option C describes a selection operation (σ), which filters rows based on conditions, not columns.

Option D is incorrect because projection does not join or combine values from different columns into a single string; it simply lists them side-by-side as part of the new schema. Therefore, Option A is the correct interpretation.