In 5G the Network function which has the similar functionalities as HLR is …a.HSSb.MMEc.UDMd.SDM

The Network function in 5G which has similar functionalities as HLR (Home Location Register) in 4G is HSS (Home Subscriber Server). So, the answer is a. HSS.

Here's a step by step explanation:

1. The Home Location Register (HLR) is a central database that contains details of each mobile phone subscriber that is authorized to use the GSM core network.

2. In 4G LTE networks, the equivalent of the HLR is the Home Subscriber Server (HSS).

3. The HSS contains the subscription-related information to support the network entities actually handling calls/sessions.

4. In 5G networks, the functionality of HSS is still present but it has been evolved into different network functions like UDM (Unified Data Management), AUSF (Authentication Server Function), etc.

5. However, the closest equivalent to HLR in 5G is still considered to be the HSS because it performs many of the same functions.

So, the answer is a. HSS.