What laboratory finding is likely in a patient with subclinical hypothyroidism?

In subclinical hypothyroidism, the primary laboratory finding is an elevated level of Thyroid Stimulating Hormone (TSH) combined with normal levels of free thyroxine (T4). This condition occurs when the thyroid gland is not producing enough hormones, prompting the pituitary gland to increase TSH production in an attempt to stimulate the thyroid.

Option C presents a TSH level of 7.7 mIU/L, which is indeed elevated, while the free T4 level is normal at 22 pmol/L. This aligns perfectly with the profile expected in subclinical hypothyroidism, as the elevated TSH indicates that the body is trying to compensate for inadequate thyroid hormone levels, while the normal free T4 confirms that the thyroid hormone levels are not significantly low enough to warrant a diagnosis of overt hypothyroidism.

In contrast, the other options reflect laboratory values that either indicate overt hypothyroidism, normal thyroid function, or hyperthyroidism. These findings deviate from the characteristics of subclinical hypothyroidism and thus do not support an accurate diagnosis.