题目解析：
【题目翻译】根据第4段，下列哪一项可能有助于推动纳图菲亚人将农业作为一种生活方式？
A：随着纳图菲亚人口的增加，气候变得不那么好客了。
B：镰刀和其他工具的发展使纳图菲人开发新型谷物成为可能。
C：纳图法时期气候发生了变化，产生了有利于种植谷物的条件。
D：来自邻近人口的日益激烈的竞争可能迫使纳图菲亚人更加密集地种植谷物。
【判定题型】：题目问的是文章中的具体细节信息，故根据题目问法可以判断本题为事实信息题。
【关键词定位】根据题干关键信息“toward farming as a way of life”定位到第四段第1句“The question of why the Natufians differed from their predecessors in these and other ways and why they made these first steps toward farming as a way of life remains unclear.”意思是：“为什么纳图菲亚人与他们的前辈在这些方面和其他方面有所不同，以及为什么他们把农业作为一种生活方式迈出了第一步，这个问题仍然不清楚。”
【逻辑分析】后文的内容就开始阐述可能的原因，“There were climate changes, of course, and growing aridity and rising population densities may have forced them to intensify the exploitation of cereals”这句话中提到了天气原因（干旱）和增长的人口密度，是迫使纳图夫人加强对谷物的开发利用的原因。
【选项分析】
A选项涵盖了天气和人口密度这2个原因，故A选项正确。
B选项：镰刀和其他工具的发展使纳图夫人能够开发利用新的农作物。首先，镰刀和其他工具的发展归根结底是由于恶劣的天气和增长的人口密度所导致的，其次这些工具也没有使纳图夫人开发利用“新的作物”故B选项排除。
C选项：纳图夫时期的天气，为种植农作物提供了有利的条件。错误，因为原文中提到了“growing aridity”意思是“越来越严重的干旱”，故C选项与原文矛盾，排除。
D选项：纳图夫与邻国竞争，促使纳图夫人种植更多的谷物。错误，因为文章没有提及这一点。
The question of why the Natufians differed from their predecessors in these and other ways and why they made these first steps toward farming as a way of life remains unclear. There were climate changes, of course, and growing aridity and rising population densities may have forced them to intensify the exploitation of cereals, which in turn might have stimulated the development of sickles and other tools and the permanent communities that make agriculture efficient. But precisely how these factors interacted with others at play is poorly understood.
