In a code language, "lee pee tin" means "Always keep smiling". What is the code for the word "Rose"? Statement I: "tin lut lee" means "Always keep left". Statement II: "dee pee" means "Rose smiling".

Introduction / Context:
This data sufficiency question uses a simple code language in which each word is represented by a code word. You are given the code for the phrase "Always keep smiling" and two additional coded sentences. The target is to identify which statement allows you to determine the code for the single word "Rose". The focus is on sufficiency, so you only need to know whether you can find the code, not necessarily to compute anything else about the language.

Given Data / Assumptions:
- Base code: "lee pee tin" means "Always keep smiling".
- Question: What is the code for "Rose"?
- Statement I: "tin lut lee" means "Always keep left".
- Statement II: "dee pee" means "Rose smiling".
- Each word corresponds to exactly one code word, and each code word corresponds to exactly one meaning within this language.

Concept / Approach:
The standard approach in code language questions is to compare sentences that share words. When two sentences share some words, the intersection of their codes must correspond to those shared words. Once the codes for certain words are known, the remaining code words in a sentence can be matched to the remaining meanings in that sentence. In data sufficiency, we must see if statement I alone, statement II alone, or a combination is required to determine the code for "Rose".

Step-by-Step Solution:
Step 1: Use the base code and statement I. From the base, "lee pee tin" means "Always keep smiling". From statement I, "tin lut lee" means "Always keep left". Step 2: The common English words between these two sentences are "Always" and "keep". The common code words are "lee" and "tin". So "lee" and "tin" represent "Always" and "keep" in some order. Step 3: That leaves the word "smiling" in the base sentence corresponding to the code "pee". It also leaves the word "left" in statement I corresponding to the code "lut". Up to this point, we have decoded "smiling" and "left", but we have not yet seen the word "Rose" in any sentence. Therefore, statement I alone does not tell us the code for "Rose". Step 4: Now use the base code and statement II. From the base, "lee pee tin" means "Always keep smiling". From statement II, "dee pee" means "Rose smiling". Step 5: The common English word here is "smiling", and the common code word is "pee". Hence "pee" corresponds to "smiling", which is consistent with what we inferred earlier. Step 6: In statement II, "dee pee" codes "Rose smiling". Since "smiling" corresponds to "pee", the remaining code word "dee" must correspond to the remaining English word "Rose". Thus, using statement II with the base information, we can determine that "dee" is the code for "Rose". Statement II alone is therefore sufficient.

Verification / Alternative check:
The mapping we obtain is internally consistent: "pee" matches "smiling" in both the base sentence and statement II. Then "dee" naturally maps to "Rose". Statement I, while useful for finding codes for "left" and confirming the patterns, is not needed to determine the code for "Rose". There is no alternative interpretation that would assign a different code to "Rose" under these constraints.

Why Other Options Are Wrong:
- Option a is wrong because statement I does not include the word "Rose" at all, so it cannot be used alone to find its code.
- Option c is incorrect because only statement II alone is sufficient; statement I alone is not.
- Option d is wrong because statements I and II together are not required; II alone already solves the problem.
- Option e is clearly wrong because we have shown that the code for "Rose" can be determined exactly from statement II plus the base information.

Common Pitfalls:
Learners sometimes assume that if two statements are given, they must be combined, overlooking that one might already be sufficient. It is also easy to ignore the base sentence and attempt to decode using only the new statements, but in data sufficiency the base information is always present and must be used. Another common mistake is to confuse which code word is common and therefore represents the shared English word.

Final Answer:
Statement II alone is sufficient to identify that "dee" is the code for "Rose", while statement I alone is not sufficient. Hence the correct data sufficiency choice is option B.