**Core Concept**
The patient's presentation of progressive headache, vomiting, blurred vision, and worsening symptoms with cough suggests an intracranial process causing increased intracranial pressure (ICP). This is due to the effects of cough-induced Valsalva maneuver, which transiently increases ICP in the setting of an intracranial mass lesion.

**Why the Correct Answer is Right**
The patient's symptoms are highly suggestive of an intracranial space-occupying lesion (ISOL), which can cause increased ICP. The progressive nature of the headache, episodes of vomiting, and blurred vision indicate a gradual increase in ICP. Coughing exacerbates the headache due to the Valsalva maneuver, which further increases ICP. This is a classic symptom of a mass lesion, such as a tumor or abscess, which can cause localized compression of the brain and increase ICP.

**Why Each Wrong Option is Incorrect**

**Option A:** Vascular headache, such as migraine or tension headache, typically presents with unilateral or bilateral headaches without progression over time. The presence of vomiting and blurred vision, along with worsening symptoms with cough, is not typical for vascular headache.

**Option C:** Intracerebral hemorrhage can present with sudden onset of severe headache, but the progression over 2 months and the association with cough-induced headache are not typical for hemorrhage.

**Option D:** Acute pyogenic meningitis typically presents with fever, headache, and stiff neck, but the progressive nature of the headache and the association with cough-induced headache are not typical for meningitis.

**Clinical Pearl / High-Yield Fact**
The cough headache is a classic symptom of increased ICP due to an intracranial mass lesion. The Valsalva maneuver, which occurs with coughing, increases ICP and exacerbates symptoms in patients with an intracranial mass lesion.

**✓ Correct Answer: B. Intracranial space occupying lesion**