Arrange the words i. Treadmill ii. Treason iii. Treacherous iv. Tread in the same order in which they would appear in a standard English dictionary.

Introduction / Context:
This question again tests dictionary ordering, this time among words beginning with T R E A or T R E. The words Treacherous, Tread, Treadmill, and Treason are similar enough that only a careful letter by letter comparison establishes the correct sequence. Such questions strengthen attention to detail when handling lexical data.

Given Data / Assumptions:

Words: Treadmill, Treason, Treacherous, Tread. Labels: i. Treadmill, ii. Treason, iii. Treacherous, iv. Tread. We apply standard dictionary rules. All words start with T R E, and some share further letters T R E A.

Concept / Approach:
Lexicographic ordering compares words from left to right. We first locate the point where letters differ and then place the word with the earlier letter first. If one word is a prefix of another, the shorter word appears earlier. In this set, Treacherous, Tread, and Treadmill share the prefix T R E A, while Treason differs slightly at the fifth letter. This influences the final ordering.

Step-by-Step Solution:
Step 1: Spell the words clearly: Treacherous (T R E A C H E R O U S), Tread (T R E A D), Treadmill (T R E A D M I L L), Treason (T R E A S O N). Step 2: All words begin with T R E A, so we compare the fifth letter. Step 3: At the fifth position, Treacherous has C, Tread has D, Treadmill has D, Treason has S. Step 4: Alphabetically, C comes before D, which comes before S. Therefore Treacherous must come first among these words. Step 5: Now compare Tread and Treadmill. Tread is T R E A D, Treadmill is T R E A D M I L L. Here, Tread is a complete word and a prefix of Treadmill. Step 6: When one word is a prefix of another, the shorter word comes first, so Tread precedes Treadmill. Step 7: Treason, with S at the fifth letter, comes after all words with C or D at that position. Step 8: Combining these findings, the order is Treacherous (iii), Tread (iv), Treadmill (i), Treason (ii), expressed as iii, iv, i, ii.

Verification / Alternative check:
To verify, quickly list only the first five letters for each word: T R E A C, T R E A D, T R E A D, T R E A S. Ordering C, D, D, S gives exactly the order Treacherous, then the Tread pair, then Treason. Within the Tread pair, the prefix rule ensures Tread before Treadmill. Mapping back to labels confirms the sequence iii, iv, i, ii.

Why Other Options Are Wrong:
The sequence ii, iii, iv, i starts with Treason, which has S at the fifth letter, even though C and D come alphabetically earlier. The sequence iii, iv, ii, i incorrectly places Treason before Treadmill, ignoring that D precedes S. The sequence i, ii, iii, iv begins with Treadmill, even though Treacherous should come first due to the C at the first differing position. The sequence iv, iii, i, ii misplaces Tread before Treacherous and does not respect the alphabetical comparison at the fifth letter.

Common Pitfalls:
Learners may be tempted to group Tread and Treadmill together and place them before Treacherous simply because they are more familiar. Another common error is to overlook the C in Treacherous and assume all words with T R E A must be checked only by length. Remembering to identify the first differing letter and then apply the prefix rule only when entire prefixes match helps keep the ordering accurate.

Final Answer:
The correct dictionary order is iii, iv, i, ii.