It's D because of the protocol number.
Ping is ICMP protocol - protocol number = 1
=> SNAT policy ID 1 is policy that used.
=> Translated address is "SNAT-Remote1" that 10.200.1.99

For a high-latency internet connection, the SSL VPN setting that should be adjusted is:
* C. SSL VPN dtls-hello-timeout: This setting determines how long the FortiGate will wait for a DTLS hello message from the client. For high-latency connections, increasing this timeout will prevent SSL VPN negotiation failures caused by delays in receiving the DTLS hello message.
The other options are not suitable:
* A. SSL VPN idle-timeout: This setting controls the idle time allowed before a session is terminated, which is not relevant to the initial connection establishment.
* B. SSL VPN login-timeout: This setting controls the maximum time allowed for a user to log in, but does not affect connection negotiation.
* D. SSL VPN session-ttl: This setting controls the total time-to-live for an SSL VPN session but does not directly address issues caused by high latency.
References
* FortiOS 7.4.1 Administration Guide - SSL VPN Configuration, page 1415.

The correct answer is:
C. Disabling split tunneling
Split tunneling allows VPN users to access both local and remote networks simultaneously. However, if you want to inspect all web traffic, including Internet traffic, coming from users connecting to the SSL- VPN, you should disable split tunneling. Disabling split tunneling forces all user traffic through the VPN tunnel, allowing you to inspect and control the traffic more effectively.

B. Loose RPF check will allow the traffic.
C. Strict RPF check will allow the traffic.