אַחַ֤ת ׀ שָׁאַ֣לְתִּי מֵֽאֵת־יְהוָה֮ אוֹתָ֪הּ אֲבַ֫קֵּ֥שׁ שִׁבְתִּ֣י בְּבֵית־יְ֭הוָה כָּל־יְמֵ֣י חַיַּ֑י לַחֲז֥וֹת בְּנֹֽעַם־יְ֝הוָ֗ה וּלְבַקֵּ֥ר בְּהֵיכָלֽוֹ׃
Modified Sefria.com translation:
One thing have I asked of the LORD, it will I seek after: a) That I may dwell in the house of the LORD all the days of my life, b) To behold the pleasantness of the LORD, and c) to visit early in His temple.
It seems that he is requesting 3 things (which I marked a, b, c) above. Why does David use the term "one thing" and "it"?