Para transformar a frase "The International Court of Hague rejected an attempt by New Zealand to stop further French nuclear tests in the South Pacific" para a forma passiva, precisamos focar no objeto da ação (neste caso, "an attempt") e fazer com que ele se torne o sujeito da nova frase. A estrutura da voz passiva em inglês geralmente segue o padrão: "sujeito + verbo to be + participio passado + agente (opcional)". Vamos analisar as alternativas: a) An attempt by New Zealand to stop further French nuclear tests in the South Pacific have been rejected by The International Court of Justice in Hague. - Incorreta, pois "have" não concorda com "an attempt" (singular). b) An attempt by New Zealand to stop further French nuclear tests in the South Pacific would be rejected by The International Court of Justice in Hague. - Incorreta, pois muda o tempo verbal para o condicional. c) An attempt by New Zealand to stop further French nuclear tests in the South Pacific was rejected by The International Court of Justice in Hague. - Correta, pois mantém o passado e a estrutura da voz passiva. d) The International Court of Justice has rejected an attempt by New Zealand to stop further French nuclear tests in the South Pacific. - Incorreta, pois está na voz ativa. e) An attempt by New Zealand to stop further French nuclear tests in the South Pacific is being rejected by The International Court of Justice in Hague. - Incorreta, pois muda o tempo verbal para o presente contínuo. Portanto, a alternativa correta é: c) An attempt by New Zealand to stop further French nuclear tests in the South Pacific was rejected by The International Court of Justice in Hague.