Answer : 1. "I want to buy a new dress, but I do not have enough money."
Explanation :

In this sentence, "I want to buy a new dress" and "I do not have enough money" are two independent clauses. When two independent clauses are joined by a coordinating conjunction (in this case, "but"), a comma should be placed before the conjunction to separate the clauses.

Let's break down each option:

• a) I want to buy a new dress, but I do not have enough money.
  • This sentence is correctly punctuated. The comma before "but" separates the two independent clauses.
• b) I want to buy a new dress but I do not have enough money.
  • This sentence is missing a comma before "but." Without the comma, it incorrectly joins two independent clauses.
• c) I want to buy a new dress, but I do not have enough money.
  • This sentence uses a semicolon before "but," which is incorrect. A semicolon is used to join closely related independent clauses that are not joined by a conjunction.
• d) I want to buy a new dress but, I do not have enough money.
  • This sentence incorrectly places the comma after "but." The comma should be before the conjunction "but" to correctly separate the two independent clauses.

Thus, option a) is the correct choice as it follows the proper punctuation rules for joining two independent clauses with a coordinating conjunction.