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).
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Question: Abstract: Mixed sequence DNA can exist in two right-handed and one left-handed double helical conformations--A, B and Z. Under conditions of high water activity the B conformation prevails. If the water activity is reduced on addition of salt or organic solvents, transformation occurs to A-DNA or, in DNAs with alternating purine-pyrimidine sequences, to the left-handed Z-DNA. In crystal structure analyses of oligonucleotides, the free oxygen atoms of adjacent phosphate groups along the polynucleotide chain in B-DNA are found at least 6.6 A apart and individually hydrated whereas they are as close as 5.3 A in A-DNA and 4.4 A in Z-DNA, and bridged by water molecules. We suggest that this more economical hydration in A- and Z-DNA compared with B-DNA is the underlying cause of B----A and B----Z transitions.
Which is the apt title for the abstract? option1: DNA conformation is determined by economics in the hydration of phosphate groups. option2: Albumin labeled with Gd-DTPA as an intravascular, blood pool-enhancing agent for MR imaging: biodistribution and imaging studies.

Answer: DNA conformation is determined by economics in the hydration of phosphate groups.

Question: Abstract: This case illustrates that massive tumor size, ulceration, or history of multiple recurrences are not absolute prerequisites for metastatic BCC. It supports the hypothesis that tumor proximity to major lymphatic systems or large-caliber blood vessels may be of significance. BCCs originating in skin overlying the parotid gland have the potential to penetrate to a rich vascular and lymphatic plexus as well as compromise the integrity of the facial nerve. Early treatment of these neoplasms utilizing accurate methods of microscopic control appears warranted to prevent the serious consequences of recurrences and deep tissue involvement.
Which is the apt title for the abstract? option1: Metastatic basal cell carcinoma originating in the supra-parotid region. option2: Relation between the frequency of colorectal adenoma and the serum cholesterol level.

Answer: Metastatic basal cell carcinoma originating in the supra-parotid region.

Question: Abstract: Eighty-two women with symmetric cornual blockage were selected for evaluation of the results of microsurgical anastomosis in relation to data from preoperative hysterosalpingography and histologic study of excised tubal specimens. Serial sections from 164 occluded tubal portions were examined. The term pregnancy rate was 44%. Several prognostic factors influencing the postoperative pregnancy rate were revealed: maximized tubal length; preserved intramural portion; absence of chronic inflammation; absence of tubal inclusion in the tubal wall; and absence of tubal endometriosis.
Which is the apt title for the abstract? option1: Prognostic factors influencing the pregnancy rate after microsurgical cornual anastomosis. option2: Fracture dislocation of the femoral head treated by open reduction and internal fixation.

Answer:
Prognostic factors influencing the pregnancy rate after microsurgical cornual anastomosis.