The correct option is A The two first
Let’s examine the sentence: “The two first lessons in the English reader are interesting to read.” The sentence uses two adjectives “first” and “two” for the noun “lessons.” When a number of adjectives are used together, the order depends on the function of the adjective. The adjective that is more true for the noun factually is kept closer to it. In the given sentence, the adjective “two” describes the noun “lessons” in terms of number and “first” describes the noun “lessons” in terms of its placement within the book. So, the adjective “two” is truer for the noun “lessons” than the adjective “first.” Hence, “two” should be placed immediately before the noun “lessons.” The correct sentence would be, “The first two lessons in the English reader are interesting to read.” The error is in the placement of adjectives in the original sentence. So, Option A is the correct answer.