What is a modular travel system typically designed for?
a. To provide a customizable and versatile setup for travel by combining different transportation modules, such as a car seat, stroller, and base unit.
b. To create a fixed and non-adjustable travel arrangement that accommodates only one type of transportation method.
c. To offer a multi-functional travel system that can be used solely for long-distance rail travel.
d. To allow the integration of various travel services, such as booking flights and hotels in a single platform.