Hajar al-Aswad is to the Ka'bah as I'tidal is to
Nikah
Talaq
Sawm
Salah
Correct answer is D
Hajar-al-Aswad is the Arabic word for black stone. The Black Stone (Arabic: ٱáúÍóÌóÑõ ٱáúÃóÓúæóÏ, al-Ḥajaru al-Aswad, 'Black Stone') is a rock set into the eastern corner of the Kaaba, the ancient building in the center of the Grand Mosque in Mecca, Saudi Arabia. It is revered by Muslims as an Islamic relic which, according to Muslim tradition, dates back to the time of Adam and Eve.
However, I'tidal means to make something straight and upright. And in terms of I'tidal, it is a form of movement to rise from the ruku' and bow down perpendicularly and straight. The law of doing I'tidal is mandatory while reading the dua is only sunnah.