Which of these milestones for women's rights occurred last?

worldwide, 780 million people do not have access to an improved water source. an estimated 2.5 billion people lack access to improved sanitation (more than 35% of the world's population)

answer: this is because archeologists keep finding artefacts and ancient ruins dated more than 10000 to 15000 years, date around scientists said humans discovered language; which is at least mysterious as scientists always have said that is necessary to have a language to have architecture and some basic maths.

explanation: brainlest