Answer is C.
Explanation;
Single replacement
reaction is a chemical reaction between an element and a compound. The
element takes the position of another element in the compound by replacing.
Common equation is
A + BC → AC + B
Al is in 13th group of
the periodic table. Hence, Al forms Al³⁺ by losing 3 electrons.
Likewise, Cl is in 17th group of the periodic table and forms Cl⁻ by gaining one electron. Hence aluminium
chloride can be written as AlCl₃.
Cs is in 1st group of
the periodic table. Hence, Cs tends to form Cs⁺ by losing an electron.
The reaction between Cs⁺ and Cl⁻ will form CsCl.
Since, this is a single replacement reaction, Al in
the AlCl₃ is replaced by Cs and
CsCl is formed. The balanced
reaction equation is
AlCl₃ + 3Cs → 3CsCl + Al
