Given an abstract, indicate which of the provided candidate titles (Option1 and Option2) best describes it (respond with the text of the title, not option1/2).

[EX Q]: Abstract: Bilateral optic atrophy is reported in two patients who, although they were long-standing users of the leaves of Catha edulis, had chewed larger quantities than usual. Since the leaves of this plant are used widely throughout its native area as the source of a mildly stimulant narcotic, the effect in these cases may be an idiosyncratic reaction to an unusually large dose.
Which is the apt title for the abstract? option1: The presumed neurotoxic effects of Catha edulis--an exotic plant now available in the United Kingdom. option2: Assessment of left ventricular diastolic function: comparison of Doppler echocardiography and gated blood pool scintigraphy [published erratum appears in J Am Coll Cardiol 1987 May;9(5):1199]
[EX A]: The presumed neurotoxic effects of Catha edulis--an exotic plant now available in the United Kingdom.

[EX Q]: Abstract: Human IgG4 antibodies directed against phospholipase A, the P1 antigen from Dermatophagoides pteronyssinus extracts, and cat albumin were found unable to cross-link antigen. Previously, it was demonstrated that IgG4 antibodies, in contrast to IgG1 antibodies, did not cross-link Sepharose-bound antigen and antigen added in solution. To eliminate the possibility that this phenomenon was caused by preferential binding of both IgG4 Fab fragments to the solid-phase-bound antigen, cross-linking of antigen was studied in a fluid-phase system. In this test, incapability of IgG4 antibodies to bridge two antigens was also found. As a result of such a phenomenon, it is expected that immune complexes formed by IgG4 antibodies will be considerably smaller than complexes formed by IgG1. This was confirmed by analysis of the molecular size profiles of IgG1- and IgG4-containing immune complexes in sucrose-density gradients. Moreover, IgG1 was able to precipitate antigen in a radioimmunoprecipitation test, whereas precipitation was not demonstrable by the same amount of IgG4 antibodies. Even 3% polyethylene glycol 8,000 did not precipitate the small IgG4-containing immune complexes efficiently. The antibodies studied were of a high-affinity type, and there was no significant difference in association constants between IgG1 and IgG4 antibodies. Therefore, we were not able to confirm observations reported in the literature that the IgG4 subclass is associated with a low-affinity antibody response; probably, the affinity of the IgG4 antibodies was underestimated by other investigators because of the polyethylene glycol precipitation technique used to separate antibody-bound and free antigen. Our findings stress the point that IgG4 antibodies take a special place in the immune response upon chronic exposure to antigen.
Which is the apt title for the abstract? option1: Serologic aspects of IgG4 antibodies. II. IgG4 antibodies form small, nonprecipitating immune complexes due to functional monovalency. option2: 'Capture' of stereopsis by illusory contours [letter]
[EX A]: Serologic aspects of IgG4 antibodies. II. IgG4 antibodies form small, nonprecipitating immune complexes due to functional monovalency.

[EX Q]: Abstract: A melanin-producing, encapsulated, histologically benign-appearing tumor of the trigeminal nerve was surgically removed from a 9-year-old boy. It recurred 6 months later and was then subtotally resected and treated with radiation therapy. The clinical and pathological features of this and 10 similar cases reported in the literature are reviewed. These tumors are best categorized as meningeal melanocytomas.
Which is the apt title for the abstract? option1: Meningeal melanocytoma. Case report and review of the clinical and histological features. option2: Preeclampsia is not associated with excess fetal clotting.
[EX A]:
Meningeal melanocytoma. Case report and review of the clinical and histological features.