In the following question on English idioms, choose the alternative which best expresses the meaning of the expression From stem to stern as used in standard usage.

Introduction / Context:
This question tests your understanding of the English idiom From stem to stern. Idioms are fixed expressions whose meanings are not always clear from the individual words. Originally, this phrase comes from the vocabulary of ships, where stem refers to the front part and stern to the rear. Over time, the idiom has also taken on a broader meaning in general English, describing something that extends through the whole length or from beginning to end.

Given Data / Assumptions:

• Idiom given: From stem to stern.
• Options include references to ships, beginnings and endings, plants, and personality changes.
• You must select the option that best captures the idiomatic sense as used in normal English sentences.
• The focus is on complete extent, not literally only ship parts or plants.

Concept / Approach:
Literally, stem and stern are parts of a ship. However, in idiomatic usage, From stem to stern means throughout the entire length or from one end to the other. This idea can be generalised to mean from the beginning to the end. While the ship based description in option a reflects the literal origin, option b expresses how the idiom is commonly used in modern writing and speech. Examination questions normally prefer the generalised meaning that applies across many contexts, such as books, houses, or processes.

Step-by-Step Solution:
Step 1: Recall or infer that stem and stern are nautical terms relating to the front and back of a ship. Step 2: Understand that the idiom has developed to mean through the whole thing or from one end to the other. Step 3: Examine option a, all the way from the front of a ship to the back. This is the literal image and is partly correct but very narrow. Step 4: Examine option b, from the beginning to the end. This captures the extended idiomatic sense that applies not only to ships but to many other situations. Step 5: Examine option c, top of a plant to its roots, which introduces plants and is unrelated to standard usage. Step 6: Examine option d, loose pleasantness to become strict, which bears no relation to the idea of extent. Step 7: Decide that option b gives the best idiomatic meaning for examination purposes.

Verification / Alternative check:
Consider a sentence such as The house was cleaned from stem to stern before the festival. Here, the subject is a house, not a ship, and the meaning is that it was cleaned thoroughly from beginning to end or from one end to the other. The use of the idiom in non nautical contexts supports option b. If the phrase were restricted only to ships, you would not see it applied to houses, books, or projects. Modern examples in newspapers and novels confirm that it is used more generally.

Why Other Options Are Wrong:
All the way from the front of a ship to the back: Captures the literal origin but misses the wider idiomatic use and is therefore too narrow.
From the top of a plant to its roots: Introduces an incorrect image that is never associated with this idiom.
Loose pleasantness to become strict: Describes a change in behaviour, not an extent in space or time, and is unrelated.

Common Pitfalls:
Learners may get stuck at the literal level and choose the option that talks about ship parts, ignoring the fact that idioms often extend beyond their original imagery. Another common error is to think that any phrase mentioning front and back is automatically correct. To avoid this, you should read example sentences of idioms in context and notice where and how they are used. Building a mental link between From stem to stern and phrases like throughout, completely, and from beginning to end will help you recall the correct meaning quickly in exams.

Final Answer:
The idiom From stem to stern means from the beginning to the end, so option b is correct.