In this cloze test sentence about motivation and anxiety, you must choose the word that best completes "However, increasing motivation beyond an ______ level tends to produce a dysfunctional result."

Introduction / Context:
This sentence is part of the same passage discussing how motivation interacts with ability, technology, and anxiety to affect job performance. The specific line focuses on the idea that motivation is beneficial only up to a certain ideal level, after which further increases may lead to problems. You must select the adjective that best expresses this idea of a best possible level of motivation.

Given Data / Assumptions:
- The sentence reads: "However, increasing motivation beyond an ______ level tends to produce a dysfunctional result because it is accompanied by an increased level of anxiety."
- Options: "certain", "desired", "increased", and "optimal".
- The passage aims to show that there is a best range of motivation, and moving beyond that range causes negative effects.

Concept / Approach:
In psychology and management, the term "optimal level" is often used to describe the best or most favourable point of a variable at which performance is maximised. Beyond this point, additional increments can reduce effectiveness. The word "optimal" exactly captures the sense of a best possible level. Words like "certain" and "desired" are vague and do not explicitly indicate that the level is the most effective one. "Increased level" does not fit grammatically in the phrase "beyond an increased level".

Step-by-Step Solution:
Step 1: Identify that the sentence talks about going beyond a best point, after which performance becomes dysfunctional. Step 2: Examine "certain". "Beyond a certain level" is possible English, but it does not emphasise that the level is the best or ideal one. Step 3: Examine "desired". "Beyond a desired level" sounds odd because "desired" refers to what someone wants, not to an objectively best point. Step 4: Examine "increased". "Beyond an increased level" is not a natural phrase and is grammatically awkward. Step 5: Examine "optimal". This word means best or most favourable and naturally fits the idea of going beyond the ideal level of motivation.

Verification / Alternative check:
If we substitute "optimal", the sentence becomes: "However, increasing motivation beyond an optimal level tends to produce a dysfunctional result because it is accompanied by an increased level of anxiety." This clearly expresses that there is a best point of motivation and that exceeding this point leads to problems. The rest of the passage, which discusses moderation and balance, supports this interpretation.

Why Other Options Are Wrong:
"Certain" is too vague and does not carry the idea of best or ideal; exam passages on performance typically use more precise terms. "Desired" suggests what someone wants rather than what is objectively optimal; it is therefore less suitable. "Increased" does not sit well after "an" and fails to create a meaningful phrase. None of these words fits the technical sense as neatly as "optimal".

Common Pitfalls:
Students sometimes pick broad words like "certain" because they seem safe and grammatically acceptable. However, in cloze tests, the exam setter often expects domain-specific vocabulary like "optimal" when discussing performance, motivation, or risk. Always keep the subject area in mind when choosing between multiple grammatically correct options.

Final Answer:
The correct word to complete the sentence is optimal, giving "increasing motivation beyond an optimal level".