Which one among the following countries does NOT have common boundary

Which one among the following countries does NOT have common boundary with South Africa ?

Zambia
Zimbabwe
Botswana
Namibia
This question was previously asked in
UPSC CAPF – 2020
The correct answer is (A) Zambia.
South Africa shares land borders with the following countries:
1. Namibia (to the northwest)
2. Botswana (to the north)
3. Zimbabwe (to the northeast)
4. Mozambique (to the east)
5. Eswatini (formerly Swaziland) (to the east)
It also completely surrounds the landlocked country of Lesotho. Zambia is located to the north of Zimbabwe and Botswana, separated from South Africa by these countries.
Zambia shares borders with the Democratic Republic of Congo, Tanzania, Malawi, Mozambique, Zimbabwe, Botswana, Namibia, and Angola. It does not share a direct border with South Africa. Zimbabwe, Botswana, and Namibia are direct neighbors of South Africa.