Step 1: All words begin with "Disco-". Compare the 6th letter of each word. Disclose has 'l', Disconnect has 'n', Discount has 'u', Discourage has 'u'. Alphabetical order: l comes before n comes before u.
Step 2: For words with the same 6th letter 'u' (Discount and Discourage), compare the 7th letter. Discount has 'n', Discourage has 'r'. 'n' comes before 'r'.
Step 3: Therefore, the dictionary order is: (b) Disclose, (d) Disconnect, (a) Discount, (c) Discourage. This matches option (D).