为了保护这些历史遗址，游客数量受到了限制的翻译：In order to protect these historic sites, number of visitors is limited 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

In order to protect these historical sites, the number of visitors has been limited

In order to protect these historic sites, number of visitors is limited

In order to protect these historical ruins, tourist quantity has been restricted

In order to protect these historical sites, number of visitors are restricted

In order to protect these historic sites, number of visitors is limited