Continuing the same passage, select the correct word to fill the blank. Sentence focus: ________ a concerted effort, primary care physicians can be trained to help people with mild and severe problems.

Introduction / Context:
This question continues the cloze passage discussing how primary care physicians can support mental health services. The blank appears before the phrase a concerted effort, and you must choose the preposition or connector that best completes the sentence. The idea is that if there is a strong, coordinated effort, these doctors can be trained to help patients with a range of problems.

Given Data / Assumptions:

• Sentence fragment: ________ a concerted effort, primary care physicians can be trained to help people with mild and severe problems.
• Options: To, For, But, With.
• The overall meaning: Given or by means of a concerted effort, training becomes possible.

Concept / Approach:
The natural way to introduce a phrase like a concerted effort when talking about the means or condition for something is with with. The expression with a concerted effort means by making a strong, coordinated effort. To, for, and but do not create a standard expression in this context. Therefore, the correct word is With.

Step-by-Step Solution:
Step 1: Understand the intended meaning: If there is a concerted effort, then training primary care physicians is possible. Step 2: Recognise that English often expresses such conditions with with + noun, as in with hard work, you can succeed. Step 3: Substitute option d, With, to obtain: With a concerted effort, primary care physicians can be trained... Step 4: Test option a, To: To a concerted effort sounds unnatural and ungrammatical here. Step 5: Test option b, For: For a concerted effort does not fit at the beginning of this sentence in the sense required. Step 6: Test option c, But, which is a conjunction used for contrast, not for introducing the means or condition. Step 7: Conclude that With is the only word that correctly and naturally completes the phrase.

Verification / Alternative check:
Compare with similar sentences: With proper planning, the project can succeed; With enough practice, you can master this skill. In each case, with + noun introduces the condition or means that makes the result possible. Applying the same structure to the passage gives a smooth and idiomatic sentence: With a concerted effort, primary care physicians can be trained to help people with mild and severe problems.

Why Other Options Are Wrong:
To is wrong because it normally introduces purpose (to succeed) or movement (to the city) and does not form a standard phrase with a concerted effort in this position. For might introduce purpose or benefit (for a cause), but starting the sentence with For a concerted effort, primary care physicians... is ungrammatical in this sense. But is wrong because it introduces contrast and requires two clauses, which is not the case here.

Common Pitfalls:
Students sometimes ignore collocations and focus only on grammar labels like preposition or conjunction. However, English fluency depends heavily on common phrase patterns such as with an effort, with great dedication, and with support. Recognising that with a concerted effort is a natural and common expression helps you immediately identify the correct answer.

Final Answer:
The correct word for the blank is With, giving: With a concerted effort, primary care physicians can be trained to help people with mild and severe problems.